The following relates generally to wireless communication, and more specifically to discontinuous reception and scheduling techniques in wireless communication systems using multiple transmission time intervals.
Wireless multiple-access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is Long Term Evolution (LTE). LTE is designed to improve spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards. LTE may use OFDMA on the downlink (DL), single-carrier frequency division multiple access (SC-FDMA) on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology.
In some examples, a wireless multiple-access communication system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, otherwise known as user equipment (UEs). In a LTE or LTE-Advanced (LTE-A) network, a set of one or more base stations may define an eNodeB (eNB). In other examples (e.g., in a next generation new radio (NR) or 5G network), a wireless multiple access communication system may include a number of smart radio heads (RHs) in communication with a number of access node controllers (ANCs), where a set of one or more RHs, in communication with an ANC, defines a base station (e.g., an eNB or gNB). A base station may communicate with a set of UEs on downlink (DL) channels (e.g., for transmissions from a base station to a UE) and uplink (UL) channels (e.g., for transmissions from a UE to a base station).
A base station in some LTE or NR deployments may transmit to one or more UEs using multiple different transmission time intervals (TTIs) that may include a shortened TTI (sTTI) that has a reduced length relative to a 1 millisecond (1 ms) or legacy LTE TTI. Users communicating using sTTIs may be referred to as low latency users. An sTTI may be a subset of one or more subframes that correspond to 1 ms or legacy TTI subframes. A base station may allocate transmission resources for sTTIs to a UE that may include time and/or frequency resources. In some cases, UEs may operate in a discontinuous reception (DRX) mode in which one or more radio components of the UE may be powered-down to conserve power. In some cases, it may be desirable to utilize DRX and provide the capability for communications using different TTI lengths.